The approach to reservoir optimization begins with the appropriate characterization of the reservoir fluid. Deficiencies in sampling methods may lead to erroneous conclusions regarding the fluids in situ, and, therefore, the exploitation strategies considered. Moreover, once sampled, the way in which fluids are recombined is often inadequate. Frequently, bottomhole samples are also problematic and must be analyzed correctly in order to infer the appropriate information about the reservoir system. This paper discusses sampling and recombination methods that improve the representation of reservoir fluids. A number of examples are provided where standard approaches to characterization are inadequate and a protocol of recombination is presented. The benefits of the approach are shown. The impact of characterization is also shown relative to allowable production rates and adherence to regulatory edicts.